The downside of a possible Rudy Giuliani presidency is that one could see him blowing up significant portions of the world and attempting to lock down the rest. The upside is that until he did these things, he'd be awfully entertaining.

It's not just Rudy's mercurial, despotic personality that can be expected to provide us with a presidency that will put the tabloids in Tabloid Heaven (or Tabloid Hell, whichever one is better for them). His mercurial, chaotic family members can be expected to give the main man a run for his money.

I've studied the American presidency quite a bit, and I can't remember a single instance of a candidate's own child announcing his or her support for one of his potential opponents. Patti Davis and Ron Reagan Jr clearly hated their father's policies but they kept quiet about it during elections.

But Caroline Giuliani, a 17-year-old who will enter Harvard in the autumn and be eligible to cast her first presidential vote in November 2008, broadcast her preference for Barack Obama over that of her dad on her Facebook page, and left it open to anyone from her (graduating) high school class or incoming college class to see. (A current Harvard student broke the story in Slate.)

Asked about it in Iowa, Rudy wisely took refuge in the old fashioned demurral, "I don't comment on children, because I want to give them the maximum degree of privacy."

I don't blame him. His son, Andrew, has had frosty relations with him over Rudy's treatment of the boy's mother, whom the ex-mayor publicly humiliated during their nasty divorce in a manner so nakedly vindictive it was positively surreal. And his current (third) wife, "Judith" (never Judi) Giuliani, is driving everyone around him nuts.

Again, with good reason. A recent Vanity Fair profile of the putative first lady puts one more in mind of Paris Hilton than Eleanor Roosevelt. In the first place, she lies about her name. It's not "Judith" according to her dad; it was always Judi when she was young. And it remained so until her second divorce.

Nowadays, you can get your head chopped off inside Rudyville merely for calling his wife by her given name. And yes, there's the matter of her second divorce, which was kept so secret it's not clear that George Bush's FISA snoops were aware of it until reporters discovered evidence of it a few weeks ago. (That makes six of them between Mr and Mrs Would-Be Leaders of the Free World, including Rudy's to his actual second cousin - a pander, as Bill Maher, jokes, for the southern vote.

Then there's the story of how the happy couple met. According to VF's Judy Bachrach: "The details of that fateful night have since been industriously hidden and altered. They met at a private school function, went one version of the story; at Coopers Classic Cars and Cigars, the former bar of Elliot Cuker, Rudy's onetime confidant, went another."

In fact, she picked up this married father of two inside an Upper East Side cigar bar he was known to frequent with his cronies after hours. The two would "canoodle," as the gossip reporters like to say, while Rudy told reporters he was teaching his young son how to play golf, a fact that first appeared in the insanely detailed Rudy reporting of muckracker Wayne Barrett, Rudy's personal journalist Inspector Javert. (The lack of golf lessons might also have something to do with the chilly father-and-son relations currently on display - that and the fact that Rudy announced his divorce to the public without mentioning it to his wife, Andrew's mum.)

Bachrach goes on to paint "Judith" as an almost perfect nightmare of ambition and control: the kind of woman who demands, in writing, to be seated next to her husband at all times; who insists on an extra seat on the plane for her Louis Vuitton handbag; and who expects, as first lady, to be included in cabinet meetings.

Well, Rudy took that one last one back. After all, Republicans may be forced to accept a nominee who is pro-choice and pro-gay rights (so pro gay-rights, in fact, he actually lived with a gay couple while divorcing his second wife for a woman who picked him up in a bar). But they won't cotton to man whose missus reminds them of Hillary.

After six years of Bush failing in virtually every manner imaginable, that's just about all that's left of Republican family values.